inetdmx is TCP based and it is standalone-only and/or its startup is too slow
this tool will start the server only if it is needed and shuts it down if it
gets idle while proxying all the TCP connections to it in the meantime.

It is hooked both from xinetd(8) or inetd(8)
(startups/proxying) and from crond(8) (idle shutdown).

Example is provided for httpd-stage-perl expected as your shadow
instance of httpd.